When Noah Espada was found guilty of a double-slaying seven years ago, the first person called to testify as the punishment phase of his death penalty trial began was former jailer Christopher Nieto.

But the guard — who since has garnered a felony theft conviction and raised suspicions of perjury — could cast doubt on the process that landed Espada on death row, the inmate's appellate attorneys argue.

Espada returned to a Bexar County courtroom Friday to ask visiting Judge Bert Richardson for a new trial.

Testimony for the ongoing hearing will continue later this month, and Richardson, who oversaw the original trial while an elected judge, isn't expected to issue a recommendation to the Texas Court of Criminal Appeals until next year.

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Nieto, who reluctantly took the stand Friday after the judge threatened to hold him in jail if he didn't show up to court, contributed significantly to the prosecution's case for lethal injection, appellate attorney Michael Gross has alleged in court documents.

The former guard testified that Espada was found with drugs in his cell and had gotten into a fight with another inmate within two months of his arrest, contributing to the argument that he would be a future danger to society even if sentenced to life.

But inmate Apolinar Soto testified Friday that Nieto planted the drugs and set up the inmate fight.

Nieto had been suspended after a fellow Bexar County sheriff's deputy had reported he overheard him tell Espada, “You're the badass that killed two people. You better hope I don't work here (in Espada's unit at the jail) on a Saturday.”

Nieto acknowledged Friday that he didn't appeal the suspension but denied having ever said those words.

Those issues weren't brought to the jury's attention, but what Nieto did testify to was true, he initially said Friday.

He admitted to quitting the Sheriff's Office after a small amount of marijuana was found in his car that had been left there by his brother-in-law. He passed a urine test and polygraph test following the incident, he said at the time.

“Pertaining to the (testimony about) the polygraph test, that was false. Nothing else,” Nieto conceded Friday, explaining that he never took one. “They were trying to get it lined up ... is what I meant.”

Nieto was joined by more than half a dozen other jailers during the trial, who said Espada was an aggressive, problem inmate.

Espada, 29, was convicted of targeting Luther “Luke” Scott in February and March 2004 after Scott fired him from Polly Esther's, a now-defunct River Walk nightclub.

After following Scott home one night, Espada broke into the wrong apartment and suffocated resident Sandra Ramos with a plastic bag tied over her head so there would be no witnesses, authorities alleged.

Days later, he found the right apartment and shot Scott in the back of the head.

Nieto, whose testimony was cut short Friday when he requested an attorney, is expected to return to the stand.